Heat sensitive recording materials are widely known. They are generally obtained by coating a substrate sheet with an aqueous dispersion containing a colorless electron donative organic compound (such as crystal violet lactone), an organic acidic compound and a binder, and then drying it. These heat sensitive recording materials are used as paper for recording information in facsimile machines, cardiograph machines and computer terminals.
It is often desired that information to be recorded be duplicated into two or three sheets. Japanese Patent Publications Nos.(examined) 36865/1979 and 43900/1979 disclose heat and pressure sensitive recording materials employing a transparent or translucent substrate sheet. It however, is difficult to read the recorded information due to transparency of the substrate sheet. It is also considered that two or more sheets of heat sensitive paper are piled up in order for a duplication. However, since paper absorbs heat in a significant amount, the temperature of an outer layer is decreased and a developed color becomes light and faint.
Further, heat sensitive recording materials which are currently available for a handy terminal, often make the surface of things dirty by its color, because they use carbon ink.